Porphyrins, essential constituents of many important biological systems, have functioned favorably ina variety of novel chemical and medicinal procedures; most recently as sensitizers in photochemical reactions and in uses as magnetic imaging contrast and cancer therapy agents. Consequently, there are concerted efforts toward synthesizing porphyrins that exhibit ideal solution behavior. Placing electron-affinic substituents (i.e. halogens) and alkyl groups on the peripheral of porphyrin rings influences the porphyrin chemical properties. Research objectives are to synthesize water-soluble tetraphenylporphyrins and related tetraarylporphyrins and investigate their solution properties. Compounds have been synthesized that contain halide substituents as well as alkyl substituted derivatives. Most recently efforts were directed toward the synthesis of water-soluble porphyrin containing fluorine substituents. Tetrakis(2-fluoro-3- sulfonatophenyl)porphyrin (TFPPS4) an Tetrakis(2,6-difluorlo-3- sulfonatophenyl)- porphyrin (TF2PPS4)) were obtained by sulfonating the halo substituted phenyl rings of Tetrakis(2-fluoro- phenyl) porphyrin (TFPP) and Tetrakis(2,6-difluorophenyl)porphyrin (TF2PP) respectively. Current efforts are directed toward the synthesis of highly electronegative water-soluble tetraphenylporphyrins, Tetrakis(2,3,4-trifluoro-4- sulfonatophenyl)porphyrin (TF3PPS4)2Tetrakis(2,3,5,6-tetrafluoro-4- sulfonato- phenyl)porphyrin (TF4PPS4) and/or mixed phenyl/halophenyl derivatives of these targeted porphyrins. Spectrophotometric aqueous pH titrations of these novel porphyrins will be carried out to determine acid and equilibrium constants. Reaction rates and thermodynamic data will be obtained from appropriate kinetics investigations. NMR spectroscopy will be employed to assist in the elucidation of porphyrin structures. Additionally, the aqueous behavior of these porphyrins chelated with biologically important transition metals will be investigated. Lastly, optical and NMR spectroscopy data will be collected to determine peripheral charge efforts on porphyrins kinetic solution behavior, and the effect of, and the degree of coordination of strongly and weakly coordinating ligands to metalloporphyrins.